Independent code review surfaced two required documentation fixes and
one growth-correctness gap. All addressed here.
Auto-fit gate (useCanvasViewport):
The previous "subtree-grew-by-count" check missed the delete-then-add
case: subtree of 6 → delete one → 5 → a different child arrives → 6
again. A length-only comparison reads no growth and the fit is
skipped, leaving the new node off-screen. Switched to an id-set
membership snapshot so any brand-new id forces the fit even when the
count is unchanged.
The gate logic is now extracted as a pure exported function
`shouldFitGrowing(currentIds, prevIds, userPannedAt, lastAutoFitAt)`
so the regression-prone decision can be unit-tested in isolation
without standing up React Flow + DOM event refs. 8 cases cover:
first-fit, empty-prior, brand-new id, status-update with user pan,
no-pan-ever, pan-before-last-fit, delete-then-add same length, and
shrink-only with user pan.
Parser parity (dotenv.go + next.config.ts):
Existing-env semantics were undocumented in both parsers. Both now
explicitly note that an explicitly-set empty string (`KEY=` from the
parent shell) counts as "set" — the file value does NOT backfill —
matching the Go (os.LookupEnv) and Node (`process.env[k] !==
undefined`) primitives.
`export ` prefix uses a literal space; `export\tFOO=bar` is
intentionally rejected. Added the same comment in both parsers
to lock in this parity invariant since the commit message claims
"if one parser changes, the other has to."
Skipped (per analysis):
- Drag-pan respect for left-click drag-pan during deploy. The
growth-check safety net means any pan gets overridden on the
next arrival anyway, which is the desired behavior for the
"watch the org deploy" use case. After deploy completes, no
more fit-deploying-org events fire so drag-pan works freely.
- Map cleanup for lastFitSubtreeIdsRef. Per-tab session, UUID
keys, tiny entries — not worth the cleanup hook.
993 canvas tests pass (8 new); Go dotenv tests pass; tsc clean.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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